Tuning - idle speed/timing questions.. HELP!

[SadbutTrue]

I'm trying to tune my 351w, which has a new cam/heads (cam is a comp cams XE274H, which has an optimal rpm range from 1800-6000, advertised duration of 274 i/ 286 e, duration at .050 of 230 i/236 e, and max lift of .520i/.523e). Rest of the engine components are in the sig below.

I'm having trouble getting it running right. It has been difficult to start (sometimes starts right up, sometimes the starter turns the motor over 4 or 5 times slowly before it kicks), feels like its missing, and has proven difficult to time correctly. I also have no experience with high-performance engines... things like idle speed, timing, etc.

My specific questions:
1) What is the ideal idle speed for this engine/cam combo? My Holley Street Avenger has a default 'fast idle' speed (i think for when the engine is warming up) of 1500, is that okay? And I'm assuming the regular idle speed should be higher than stock type engines (which I usually set at 600-700)... what should that be?

2) We installed a new harmonic balancer with the engine. Its timing marks seem to be way off. Is this common? It currently indicates (with the engine running) that the engine is pullying between 45 and 55 degrees (eyeballing it of course, the marks don't actually go that high) of initial timing. The piece itself seems nice, its a 'Professional Products' press-fit balancer from PAW. I'm pretty sure you can't install the balancer at the wrong angle... am I right?

3) My engine is still hard to start (as described above, and in a thread I made a week ago or so), and feels like its missing while driving... it has a herky-jerky feeling while driving around. The sensation fades a little with rpm but is still noticeable.

Some people had said if it isn't timed right that might explain the hard starting, and probably could explain the missing sensation.

How should I go about timing the engine, since the marks appear useless? Just find peak vacuum? How much vacuum should it pull?

4 Somewhat related, is it possible that I installed the distributor a tooth or two off either way? Would the engine run like that?

5) Anything I'm missing?

Thanks a ton!

 

[blown65]

Well, couple things you can do to check the balancer cause thats where I'd start. Pull the #1 plug, and crank over till the piston is at TDC, you can get it pretty close and see if its way off or pretty close. Or you can use a piston stop in the plug hole and hand crank it over both ways and find center there.

Then set initial timing around 12-14 degrees.

 

[D.Hearne]

Sounds like its retarded too much. And do as Blown65 said and check the balancer marks first. As for it's lowest idle speed, that'll depend on how much advance you give it initially. It should idle somewhere between 700-1000 rpms. Do the timing first, then the idle speed setting, then play with the mixture screws to fine tune the idle. If the timing marks are off, then it's really not a nice piece of a balancer. It'll only go on one way with the slot lined on the crank key. The balancer is the correct one to match the timing cover & pointer, right?

 

[SadbutTrue]

Sounds like its retarded too much. And do as Blown65 said and check the balancer marks first. As for it's lowest idle speed, that'll depend on how much advance you give it initially. It should idle somewhere between 700-1000 rpms. Do the timing first, then the idle speed setting, then play with the mixture screws to fine tune the idle. If the timing marks are off, then it's really not a nice piece of a balancer. It'll only go on one way with the slot lined on the crank key. The balancer is the correct one to match the timing cover & pointer, right?

The balancer is aftermarket, the timing cover and pointer are stock. The directions did not mention needing to replace those. So I assume so, but can't say I'm 100% sure.

Is it possible that I didn't like up the distributor right? Or would the car simply not run if it was off (the car does run, I've driven it about 50 miles since completing the swap and at times it feels fine...).

 

[oz]

I could be way off here but I seem to remember that the pointer changed from one side to the other at some point on Windsor engines. The pointer being off won't harm anything but you'll find it impossible to time your engine without the proper pointer. Hard cranking is usually an indicator of too much initial timing.

I don't have a 351 but I know early and late 302's have different weight balancers. 28oz and 50oz I think.... not sure if the 351 changed too but make sure yours is right for your engine. I think it yours was not right you'd know for sure.

I think you probably need a different pointer. Call the place you bought the balancer and ask them about your specific engine and pointer requirement when using their balancer.

Regarding the distributor 'being a tooth or two off'. This really doesn't mean anything. You can still get the engine properly timed but you may find that the distributor hits something on the engine as you adjust it before you achieve the timing you want. In other words, you can install the distributor in any orientation you like but the connectors, etc that come from it won't clear the rest of the engine unless it's pretty close to its intended position.

Idle speed - my guess is that you'll end up between 850 and 900 rpm w/ 12 - 16 inches of vacuum

 

[SadbutTrue]

I could be way off here but I seem to remember that the pointer changed from one side to the other at some point on Windsor engines. The pointer being off won't harm anything but you'll find it impossible to time your engine without the proper pointer. Hard cranking is usually an indicator of too much initial timing.

I don't have a 351 but I know early and late 302's have different weight balancers. 28oz and 50oz I think.... not sure if the 351 changed too but make sure yours is right for your engine. I think it yours was not right you'd know for sure.

I think you probably need a different pointer. Call the place you bought the balancer and ask them about your specific engine and pointer requirement when using their balancer.

Regarding the distributor 'being a tooth or two off'. This really doesn't mean anything. You can still get the engine properly timed but you may find that the distributor hits something on the engine as you adjust it before you achieve the timing you want. In other words, you can install the distributor in any orientation you like but the connectors, etc that come from it won't clear the rest of the engine unless it's pretty close to its intended position.

The 351w's always had 28 oz imbalance, which is what i got on the balancer. Actually, when it hasn't felt like it was missing, both my dad and I noted it seemed to rev much smoother, so i don't think balance is an issue.

The timing pointer being changed at some point is something I had not heard. Can anyone verify that?

Also, does the 'fast idle' speed of 1500 sound right? The Holley manual says that the fast idle is supposed to be 1500, again because I'm assuming its trying to warm the engine up, before dropping to the standard idle of 700-1000.

Thanks again..

 

[SadbutTrue]

Okay, might have answered one question... according to the installation instructions, the balancer has 3 sets of timing marks, but its possible that none will lineup with some pointers. Apparently Ford did use at least 3 different pointers on SBFs. Its likely I'm using an incorrect pointer.

So does anyone know what the easiest way to tell the pointer you need? And where to get it?

 

[BarnStang]

THe pointer can be anywhere you want. It's all reletive. meaing, releitive to where TDC is...Get the engine to TDC on the compression stroke then scribe a line at zero degrees on the balancer where the pointer shows zero. TDC=zero degrees. THe line and pointer can be whatever you want as long as YOU know where TDC is. You can also order a timing tape and put on your balancer with TDC set and zero on the tape goes down at zero on the pointer. THen you can actually read the timing with a light.
It sounded like it was way advanced to me too. Back the timing off a bit and drive it. You can time it by ear and by driving till you find a spot that runs nice for now.

 

[blown65]

Your not going to know jack till you do what both hearne and I stated, pull the number one plug, crank over till you have it coming on compression stroke. Feel till no air is coming out of the plug hole. At that point, you will be very close to TDC and look at the marks on your timing pointer, if its way off then you have to dig deeper, but if its close then your probably ok. No reason to do things 10 steps in front if the one thing is way off.

I should add, our Shelby engine was setup for the timing pointer to be on the pass side, of which I had to change cause of the change to the car. With the pointer on the driver side, it was at 105 degrees at TDC. Further, my Stang will idle just fine from 15 degrees to about 45 degrees. If you have vacuum advance or mech advance pulling on a 30 degree initial your in a world of trouble. You need to have this part right.

 

[mustangman1974]

1500 is what I have my fast idle set to on my edlebrock. Ford made 3 timing pointers on early SBF 2 that were on the drivers side of the engine; one cast pointer and one bolt on pointer; and the passenger side bolt on pointer. The 2 driver's side are different enough you can guest-a mate which time set is the correct ones.

 

[woodsnake]

Is your vacuum advance plugged when you are trying to set initial timing? Do you have any vacuum leaks around the intake manifold?

 

[D.Hearne]

He can only use one of the three pointers, depending on what waterpump is on it. If he's got a drivers side pump, he has to use the passenger side pointer. If he's got a passenger side pump, he'll need to use a drviers side pointer. Hard to start and crank can be either too little or too much timing. His discription of "herky-jerky" while driving it indicates the timing's retarded

 

[SadbutTrue]

He can only use one of the three pointers, depending on what waterpump is on it. If he's got a drivers side pump, he has to use the passenger side pointer. If he's got a passenger side pump, he'll need to use a drviers side pointer. Hard to start and crank can be either too little or too much timing. His discription of "herky-jerky" while driving it indicates the timing's retarded

So the two driver's side pointers are water pump specific (I'm still under the impression that there are 3 types of pointers total, 1 on passenger side and 2 different drivers side ones, I have a driver side one atm)? Glad I didn't get a new water pump already, I suppose.

I'm gonna try this tomorrow. Got a couple things I need to correct, based on this thread. Gonna have to restore the fast idle to 1500, and then set the regular idle speed to somewhere around 800-900. Also going to replace the plug wires... my dad went out and bought a Pep Boys set (which I wouldnt have done, but a plug wire is a plug wire and my old Pertronix set had a lot of corrosion on em for some reason, even though they were only a few years old). I gapped the plugs as per MSD's instructions and they're brand new, so those should be okay. Rotor/dist. cap are new as well.

So if we use a push button to manually crank it over, whats the easiest way to stop it exactly at TDC?

Once I get it to TDC, should I just forget the pointer and (perhaps using the old balancer/protractor/the marks already on the balancer as references) just make my own marks for -10, 0, 10, 20 etc on the balancer?

Thanks again, will update.

 

[oz]

Based on what you have said, I'm guessing you need a passenger side pointer. You have a drivers side one now and the timing marks are no where near close tells me you need to put it on the passenger side. Take the timing light and point it at the balancer on the passenger side while the car is running. Can you see the timing marks? If so, you need a pointer for that side.

If you must find TDC, you can't stop it at exactly TDC with a remote button. You're going to have to put a socket on the balancer bolt and turn it manually. If it were me, I'd take the #1 plug out and stick something not too hard down in the cylinder that will stick out the top and then rotate the engine until the object does not push out anymore. This will get you within 5 degrees.

Also, fast idle of 1500 is correct.

 

[SadbutTrue]

Based on what you have said, I'm guessing you need a passenger side pointer. You have a drivers side one now and the timing marks are no where near close tells me you need to put it on the passenger side. Take the timing light and point it at the balancer on the passenger side while the car is running. Can you see the timing marks? If so, you need a pointer for that side.

If you must find TDC, you can't stop it at exactly TDC with a remote button. You're going to have to put a socket on the balancer bolt and turn it manually. If it were me, I'd take the #1 plug out and stick something not too hard down in the cylinder that will stick out the top and then rotate the engine until the object does not push out anymore. This will get you within 5 degrees.

Also, fast idle of 1500 is correct.

Cool thanks. Any ideas for the object? Pencil or something (obviously one that won't leave fragments or anything behind)?

 

[66forfun]

If the pointer is wrong, I would pick up timing tape for the balancer at the local parts store. The tape is applied on the balancer giving you 0deg where ever you want it and it only costs a few bucks. Timing by ear for me was always a good warm up then find a nice hill and do a few full throttle passes up the hill, advance timing till it pings then back off a bit, then make sure she cranks over good while hot. Easy enough.

 

[woodsnake]

"We installed a new harmonic balancer with the engine. Its timing marks seem to be way off. Is this common? It currently indicates (with the engine running) that the engine is pullying between 45 and 55 degrees (eyeballing it of course, the marks don't actually go that high) of initial timing. The piece itself seems nice, its a 'Professional Products' press-fit balancer from PAW. I'm pretty sure you can't install the balancer at the wrong angle... am I right?"


You can always start back at the beginning. You said the timing set was installed straight up, dot to dot, right? Get number one to TDC as described earlier, and see where your rotor is at.

You can make adjustments by moving the wires, or pulling and re-sinking the distributor. All that being said, you are shooting for an initial timing in the 8-16 deg range, with an idle around ~ 750~ or so. I'm going thru the same thing on my 68. One tooth one way, timing is at zero on the balancer, with the canister all the way into the water neck. One spot CW on the cap, and now my initial is 20 on the balalncer, with the canister all the way into the DS valve cover.
Grrr.


When you have number one at TDC, look at your balancer and see which set of timing marks your pointer lines up with, that should be what you need. I bought a summit damper, it was the same thing, three sets of marks.
When I went to school they really hammered the three check list items, #1 TDC, rotor at #1 plug, and timing pointer "zero". Then try and start it up.








You'll just have to keep at it. I want to find out what your dyno numbers are!!

 

[D.Hearne]

So the two driver's side pointers are water pump specific (I'm still under the impression that there are 3 types of pointers total, 1 on passenger side and 2 different drivers side ones, I have a driver side one atm)? Glad I didn't get a new water pump already, I suppose.

I'm gonna try this tomorrow. Got a couple things I need to correct, based on this thread. Gonna have to restore the fast idle to 1500, and then set the regular idle speed to somewhere around 800-900. Also going to replace the plug wires... my dad went out and bought a Pep Boys set (which I wouldnt have done, but a plug wire is a plug wire and my old Pertronix set had a lot of corrosion on em for some reason, even though they were only a few years old). I gapped the plugs as per MSD's instructions and they're brand new, so those should be okay. Rotor/dist. cap are new as well.

So if we use a push button to manually crank it over, whats the easiest way to stop it exactly at TDC?

Once I get it to TDC, should I just forget the pointer and (perhaps using the old balancer/protractor/the marks already on the balancer as references) just make my own marks for -10, 0, 10, 20 etc on the balancer?

Thanks again, will update.

Sorry it took so long to get back, we've flown out to see my son at Camp Pendleton Ca. The pointer you need depends on the waterpump you're using. Passengerside pump inlet, you'll need a drivers side pointer. Drivers side inlet, you need a passenger side pointer. Once you've got that figured, then rotate the crank to align the pointer with the timing marks. Get the piston as close to TDC as possible, then use a breaker bar & socket to align them. If the piston's at TDC and the distributor rotor is way off, you need to rotate the crank another full round to TDC. Two revs of the crank for each rev of the distributor.

 

[SadbutTrue]

"We installed a new harmonic balancer with the engine. Its timing marks seem to be way off. Is this common? It currently indicates (with the engine running) that the engine is pullying between 45 and 55 degrees (eyeballing it of course, the marks don't actually go that high) of initial timing. The piece itself seems nice, its a 'Professional Products' press-fit balancer from PAW. I'm pretty sure you can't install the balancer at the wrong angle... am I right?"

You can always start back at the beginning. You said the timing set was installed straight up, dot to dot, right? Get number one to TDC as described earlier, and see where your rotor is at.

You can make adjustments by moving the wires, or pulling and re-sinking the distributor. All that being said, you are shooting for an initial timing in the 8-16 deg range, with an idle around ~ 750~ or so. I'm going thru the same thing on my 68. One tooth one way, timing is at zero on the balancer, with the canister all the way into the water neck. One spot CW on the cap, and now my initial is 20 on the balalncer, with the canister all the way into the DS valve cover.
Grrr.

When you have number one at TDC, look at your balancer and see which set of timing marks your pointer lines up with, that should be what you need. I bought a summit damper, it was the same thing, three sets of marks.
When I went to school they really hammered the three check list items, #1 TDC, rotor at #1 plug, and timing pointer "zero". Then try and start it up.

You'll just have to keep at it. I want to find out what your dyno numbers are!!

Trust me, I do too. I'll be trying all this tonight hopefully... didn't get a chance this weekend.

Any recommendations for semi-inexpensive spark plug wires? My Pertronix ones were all corroded for some reason (not sure why, they weren't even 2 years old). My dad picked up some standard/stock style ones from Pep Boys... are they gonna be enough (I guess a spark plug wire is a spark plug wire, but I have a hotter coil/MSD so I wanna make sure they all work together well).

Hearne:
Sorry it took so long to get back, we've flown out to see my son at Camp Pendleton Ca. The pointer you need depends on the waterpump you're using. Passengerside pump inlet, you'll need a drivers side pointer. Drivers side inlet, you need a passenger side pointer. Once you've got that figured, then rotate the crank to align the pointer with the timing marks. Get the piston as close to TDC as possible, then use a breaker bar & socket to align them. If the piston's at TDC and the distributor rotor is way off, you need to rotate the crank another full round to TDC. Two revs of the crank for each rev of the distributor.

No worries. Damn cool thing your son is doing (I'm assuming he's a Marine ). You shoulda just made the hour and a half drive up to Thousand Oaks while you were out here, I'ms ure you would have had it running like a top in 20 minutes

So is there only one pointer for each outlet style water pump? I'm strongly considering saying forget the pointer and making my own marks, perhaps with timing tape as was suggested earlier.

 

[D.Hearne]

There's two pointers for the passenger side pump cover. One is bolted on the cover, the other is cast into it. The drivers side cover had one pointer position, with at least two bolt on pointers I know of. (family) If We had time we would go up there. Got too many of us here to get away. My son's a Cpl in the Marines, works on the LAV's. Hope this helps. Got to run.